Rubber-dam holder and cutter.



No.896 662. v BATENTED AUG. 1a, 1908.

A. PRENTIS.

RUBBER DAM HOLDER AND CUTTER.

' 'APPLIOATION FILED my 21, 1908.

u 7 :4 illllllllllllllll llfll lllnllinl] I I w/ NESSES 5 4/ INVENTOR AUGUSTUS 13.. PHENTIS mm VF 1 A TTORNEYS AGUSTUS BRANDEGEE PRENTIS, OF BANDON, OREGON.

RUBBER-DAM HOLDER AND CUTTER.

T 0 all whom it may concern:

Be it known that I,AeUsTUs BRANDEGEE PREN'rIs, a citizen of the United States, and a resident of Bandon, in the county of Coos and State of Oregon, have invented certain new and useful Improvements in Rubber-Dam Holders and Cutters, of which the following is a specification.

My invention relates to improvements in rubber dam holders and cutters and consists in certain novel constructions and combinations of parts, hereinafter described and claimed.

Referring to the drawings forming a part hereof, Figure 1 is a perspective view of the improvement, and Fig. 2 is a transverse vertical section.

The present embodiment of my invention comprises a support having a bottom and ends 1, and open at its front and top as shown. Each of the ends of the support is provided with a square bearing 4, in which is received the trunnion 5 of a cylindrical casing 6, having one end open, and normally closed by a cover 7, and provided through its lower surface with a slot 8, for a purpose to be presently described.

The rubber dam 9 in the form of a roll, is inserted in the cylindrical casing by removing the cover 7, and the free end of the dam is passed downwardly through the slot 8, and under a rod 10, extending longitudinally of the support. From the rod 10 the dam extends forward and out at the front of the support between the bottom which is extended as at 11, and a swinging frame comprising a body portion 12, and arms 13 pivoted on a rod 14, extend from end to end of the support, the body portion 12 of the swinging yoke being pressed into engagement with the dam by a spring 14, having a coil 15 encircling the rod 14, and arms 16 extending rearwardly, and engaging the rod 10.

A lug 16 is connected with the inner face of the body portion of the swinging yoke, and the lower end of a rod 17 is rotatably mounted on the lug, the said rod being threaded at its center through a lug 18 on a bearing 19 arranged at the front of the support, and having arms 20 connected with the support as at 21. A collar 22 is secured to the rod above the lug 18, and a handle 23 is provided for convenience in manipulating the rod.

A guide bar 24 is provided at the front of the frame below and to the front of the hearing 19, the said bar being of greater length Specification of Letters Patent.

Application filed May 21, 1908.

provided with Patented Aug. 18, 1908.

Serial No. 434,142.

than the support, the free ends 25 thereof being bent at right angles to the body portion of the bearing, thence parallel with the body portion as at 26, and again at right angles as at 27, and secured to the ends of the support as at 28.

A block 29 is slidably mounted on the bearing, the said block being provided with an opening through which extends the bar, and secured to the block by screws 30, is a blade 40, the cutting edge 41 of the blade being inclined with respect to the bar as shown in Fig. 1, and cutting against the edge of the extended bottom 11, which edge acts as a ledger blade. The block is provided with a handle 31 for convenience in 1nanipulating the same.

In operation, the rubber dam being ar ranged as shown in Fig. 2, when it is desired to remove a portion from the roll, the rod 17 is turned to loosen the swinging yoke, to permit the dam to be drawn thereunder, until a suitable length has been withdrawn. The rod is now turned to clamp the dam, and the block 29 is moved to the left of Fig. 1, thus cutting off the withdrawn portion of the dam.

The knife blade is easily removed from the block for sharpening or for interchanging, and it will be noticed that the trunnions of the cylindrical casing are square in cross section, which prevents turning of said casing in the support.

I claim:

1. A rubber dam holder, comprising a support, having an open front and top, and provided in its ends with open bearings, a cylindrical casing for receiving the dam, and having trunnions engaging the bearings and a longitudinal slit, a rod arranged transversely of the support below and behind the slit, and over which the dam passes, a swinging yoke, bearing upon thedam in front of the rod, springs acting to normally forcethe yoke against the dam, means for raising and lowering the yoke, a guide bar at the front of the support, a block slidable on the bar and provided with a handle, a knife blade detachably connected with the block, andhaving its cutting edge inclined, the bottom of the support being extended to co-act with the blade as a ledger blade.

2. A rubber dam holder, comprising a support, a cylindrical casing, for receiving the dam mounted in the support, said casing having a longitudinal slit to permit the passage of the dam, a spring pressed yoke en'- gaging the dam for clamping it against the bottom of the su port, a bar at the front of the support, a b ock slidable on the bar, a knife blade having an inclined cutting edge,

detachably connected with the block, the

bottom of the support being extended to co-act with the blade as a ledger blade.

3. A rubber dam holder, comprising a support having an extended base, means for supporting the darn, a spring pressed swinging yoke, bearing against the extended base for clamping the dam, means for raising and lowering the yoke, a guide bar at the front of the support, a knife provided with an inclined cutting edge slidable on the bar, and

co-acting with the extended base of the support, for the purpose set forth.

4. A rubber dam holder comprising a support provided with dam supporting means, a swinging yoke for clamping the dam, means for raising and lowering the yoke, a guide bar at the front of the frame, and a knife slidable on the bar, the support being provided with an extended base for cooperating with the yoke and with the knife.

AGUSTUS BRANDEGEE PRENTIS. 

